1. Field of the Invention
The invention relates to a beverage dispensing device which creates the illusion of liquid droplets which appear to rise despite the act of filling a drinking glass.
2. Description of the Prior Art
Flashing light sources and stroboscopic techniques have been used to create the illusion of stopped and reversed motion on apparatus moving or spinning at a high repetitive rate. A fan, for example, spinning at a high rate of speed which is invisible to the eye can be made to appear to be stopped or moving at a slow rate, backwards or forwards, by applying a flashing light source. A detailed explanation of these effects is disclosed in Electronic Flash, Strobe by Harold Edgerton, MIT Press, Cambridge, Mass., 1979.
If the flashing light source is pulsed at a very high frequency, the eye may be tricked into perceiving a constantly illuminated source. A movie projector actually flashes at 24 frames per second although the eye only perceives a continuously lighted screen. As the intensity of the individual flash increases, the number of flashes per second necessary to give the illusion of constant illumination also increases in a nonlinear fashion. Information on the flicker-fusion phenomena is disclosed in Cornsweet, T. N., Visual Perception, Academic Press, N.Y., 1970, and Gregory, R. L., Eye and Brain, McGraw-Hill, N.Y., 1973.
It is known in the prior art that the limitations of the electro-optical systems of stroboscopes dictate very low light levels as the frequency of pulsation increases. If a test engineer is studying the motion of a shaft turning at the high rate of 6000 revolutions per minute with the aid of a strobe flashing at nearly the same rate, he will be able to freeze the motion of the shaft only partly. Unless the environment is completely dark, the limited illumination available from the strobe at the high frequency will combine with the ambient light to present a combination of a blurred and nearly stationary shaft.
In the prior art no method has been devised to allow viewing the illusion of pulsed liquid droplets frozen in motion by the illumination of a flashing light source in nearly ambient or even dim lighting situations. Even under completely dark conditions a fluorescent dye must be added to the liquid for the illusion to be seen clearly.